CAIRO - The brother of al Qaeda leader Ayman al-Zawahri has been arrested by police in Egypt, security sources said Saturday.

Mohammed
al-Zawahri, the younger brother of the terror network leader, was
detained at a checkpoint in the Cairo suburb of Giza, the sources said.

He
has been a vocal supporter of ousted President Mohammed Morsi, Morsi's
Muslim Brotherhood movement and the more extreme group to which he
belongs, Al Gama'a Al Islamiya.

The arrest of the younger
al-Zawahri came as more than 1,000 Brotherhood supporters and others
opposed to the military's overthrow of Islamist Morsi were detained
Friday as mass protests turned violent.

Mohammed al-Zawahri was
transferred from a police station to a maximum security prison out of
concern his supporters would attempt to free him from the police
station, the sources said. Police stations have been coming under attack
in recent days.

Usually a suspect is not transferred to a maximum security prison until after conviction.

An
Egyptian government official said Saturday that 173 people had died and
more than 1,000 had been wounded in the clashes that began Friday.

The
violence continued Saturday with an outbreak of gunfire near the
al-Fath mosque in Cairo where a group of protesters had barricaded
themselves inside.